title: Vitamin D status and mortality in chronic kidney disease.
abstract: BACKGROUND
  Vitamin D deficiency is found in the majority of patients with chronic kidney disease (CKD) and may contribute to various chronic diseases. Current guidelines suggest correcting reduced 25-hydroxyvitamin D [25(OH)D] concentrations in CKD patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2). Whether low 25(OH)D levels in these patients are associated with higher mortality is unclear. This issue was addressed in the present work.
  
  
  METHODS
  We examined 444 patients with eGFR <60 mL/min/1.73 m(2) from the Ludwigshafen Risk and Cardiovascular Health Study. This prospective cohort study includes Caucasian patients without primary kidney disease who were routinely referred to coronary angiography at baseline (1997-2000).
  
  
  RESULTS
  During a median follow-up time of 9.4 years, 227 patients died including 159 deaths from cardiovascular causes. Multivariate adjusted hazard ratios (HRs) (with 95% confidence intervals) in severely vitamin D-deficient [25(OH)D <10 ng/mL] compared to vitamin D-sufficient patients [25(OH)D ≥ 30 ng/mL] were 3.79 (1.71-8.43) for all-cause and 5.61 (1.89-16.6) for cardiovascular mortality. Adjusted HRs per 10 ng/mL increase in 25(OH)D levels were 0.63 (0.50-0.79) for all-cause and 0.59 (0.45-0.79) for cardiovascular mortality. There was no significant interaction with parathyroid hormone concentrations.
  
  
  CONCLUSIONS
  Low 25(OH)D levels are associated with increased all-cause and cardiovascular mortality in CKD patients. These findings support suggestions to correct vitamin D deficiency, but whether vitamin D supplementation improves survival remains to be proven in randomized controlled trials.
authors.affiliation: Department of Internal Medicine, Division of Endocrinology and Metabolism, Medical University of Graz, Graz, Austria. stefan.pilz@chello.at
authors.forename: Stefan
authors.initials: S
authors.lastname: Pilz
authors.forename: Andreas
authors.initials: A
authors.lastname: Tomaschitz
authors.forename: Claudia
authors.initials: C
authors.lastname: Friedl
authors.forename: Karin
authors.initials: K
authors.lastname: Amrein
authors.forename: Christiane
authors.initials: C
authors.lastname: Drechsler
authors.forename: Eberhard
authors.initials: E
authors.lastname: Ritz
authors.forename: Bernhard O
authors.initials: BO
authors.lastname: Boehm
authors.forename: Tanja B
authors.initials: TB
authors.lastname: Grammer
authors.forename: Winfried
authors.initials: W
authors.lastname: März
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology* / Q000401:mortality*; D017023:Coronary Angiography; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications* / Q000401:mortality*; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000209:etiology* / Q000401:mortality*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D